So from what I observed, there are some that I think that might add to it's aura that's why we do play on them.
1. Incentives and Rewards - majority of casinos have this membership card, and so when you play and you used it, you will accumulate points and you can used this points like to get free merchandise from them. I even have been given free hotel accommodation.
2. Design of casinos - it was really brilliantly crafted by the design itself, very big, no clocks inside, and then the color could have played as well, like gold and red which they say is the lucky color or color of money.
3. Free drinks/alcohol and then there are live band - So they gave you free drinks and alcohol, but perhaps you make you drunk and so your judgement is clouded and potentially you losing big money. And then there are entertainment, such as live bands performing every hour to keep you inside and watch and have some fun while at the same time losing money.
Maybe you can add to it as what are you think we keep on coming back as if we are under the spell of this big casinos?
Not gonna lie, the main reason why 90% of gamblers keep coming back is the hope that they can still win, this is what makes money for casino businesses, only very limited numbers of gamblers gamble for other reasons like the games or the free rewards, even those who have free rewards still complains that they don't make anything with the freebies, it shows how so many gamblers won't the bag only, it is why they keep coming back and sadly it is why they keep losing big amount of money, I am not surprised.